patch 8.1.1679: test using SwapExists autocommand file may fail

Problem:    Test using SwapExists autocommand file may fail.
Solution:   Remove the SwapExists autocommand.

Author: brammool

src/testdir/test_window_cmd.vim

@@ -42,6 +42,8 @@ function Test_window_cmd_wincmd_gf()
   function s:swap_exists()
     let v:swapchoice = s:swap_choice
   endfunc
+  " Remove the catch-all that runtest.vim adds
+  au! SwapExists
   augroup test_window_cmd_wincmd_gf
     autocmd!
     exec "autocmd SwapExists " . fname . " call s:swap_exists()"

src/version.c

@@ -777,6 +777,8 @@ static char *(features[]) =
 
 static int included_patches[] =
 {   /* Add new patch number below this line */
+/**/
+    1679,
 /**/
     1678,
 /**/